The agreement, honed and refined throughout fall 2008, was made public in November. A total of 40 attorneys general endorsed the deal, including those from Tennessee, Washington, Colorado and Arizona (notable exceptions include Florida, Texas, California, Missouri, Minnesota and New York).

Craigslist CEO Buckmaster says the company is doing its best to comply with the Connecticut attorney general's concerns.

"There are far more—and far more graphic—images on all of the general-purpose Internet portals and general-purpose search engines than anyone is ever going to find on Craigslist," says Buckmaster. "That said, we aren't comfortable with any pornographic images being posted on Craigslist, and we're committed to eliminating that."

Nick Vlcek

Craig Newmark speaks about internet safety at the Concert for Katherine

Nick Vlcek

Craig Newmark speaks about internet safety at the Concert for Katherine

* * *

Inside the Scott County, Minnesota, courtroom, the parents of Katherine Olson sat across the aisle from the parents of Michael Anderson as though they were in a wedding they never wanted. Surrounding them were more Olson family members, friends, parishioners from Rolf's church, and law-enforcement personnel involved with the case. The 40-seat gallery was filled to capacity.

Anderson entered the courtroom in a blue suit and kept to himself as his attorney, Alan Margoles, detailed his sex life.

"Remember," said Margoles. "Michael Anderson was a dumb kid. He had no girlfriend, never dated, never went to a high school dance and never held a girl's hand."

Margoles wanted to show that his client lured Katherine to the home in Savage for sex, and not, as prosecutors put forth, with the intention to kill.

The opening day saw Nancy Olson take the stand to tell the jury about the final time she saw her daughter. It was when Katherine was singing in church choir.

Prosecutors asked when she saw her daughter next.

"The next time I saw her, she was in a casket at Morris Nilsen Funeral Home," Nancy said. "And she was cold and smelled like chemicals."

The next day, Barbara Anderson took the stand to talk about her son. The soft-spoken mother wore her hair parted in the center and politely detailed how, on the day of the murder, Michael had come home from work just like any other day. "That's just Michael," Barbara would say later. "He never really talked unless he had a fun time off-roading in his truck."

Prior to the hearing, Craigslist had helped law enforcement by assembling a 127-page dossier on Anderson's use of the website. The company also dispatched Clint Powell to take the stand. The customer-service manager was familiar with the technical workings of Craigslist.

Powell told the courtroom how Anderson first used Craigslist as a way to find ice-fishing gear, truck parts and collectible plates with misspelled words such as "Star Terk." This pattern changed in October, as Anderson started trolling for women. Powell read various postings made by Anderson. One said, "looks and size don't mean a lot to me. I'm not little man, but I'm not huge either." Another read, "Looking for fresh faces for a new video and website. . . . new talent only. Also need 18-plus virgin willing to be in a video."

The entire time, Anderson sat motionless, staring straight ahead.

"I don't think he made eye contact with a single person the entire trial," says Margoles. "He was the quietest defendant I've ever had."

On day five of the trial, Anderson's former cellmate, Gregory Wikan, took the stand. He told the jury how Anderson had boasted about being known as the "Craigslist Killer."

Again, Anderson stared straight ahead, refusing to make eye contact.

The final day of testimony saw Detective Laura Kvasnicka take the stand as the last witness. She detailed the life Anderson led online, including multiple attempts to lure women to his home. He looked for no-strings-attached hook-ups, posting one such advertisement just hours before killing Katherine.

It took five hours for the jury to return its verdict. The Olson family held one another as the 12-member jury announced the news: Michael Anderson was guilty of first- and second-degree murder, as well as second-degree manslaughter.

The following morning, Judge Mary Theisen addressed the Olson family with watering eyes. She told them that Katherine's life had touched the entire courtroom.

The sympathy turned to rage as her gaze fell on Anderson. "You're a callous, cruel and unjust human being," Theisen said, sentencing Anderson to a mandatory term of life in prison without parole.

* * *

On an unseasonably snowy March 20 in New York City, George Weber—a passionate, affable 47-year-old radio newsman for WABC—posted a Craigslist ad looking for rough sex.

His solicitation was answered promptly by 16-year-old John Katehis, a self-described sadomasochist and Satanist who lived with his separated parents in the East Elmhurst neighborhood of Queens. "I can smother somebody for $60," he wrote to Weber. In the context of what was to be a sadomasochistic romp, Katehis' aggressive reply failed to raise red flags.

The two met in Brooklyn and made their way to Weber's first-floor brownstone apartment in Carroll Gardens. There, Katehis allegedly stabbed Weber some 50 times in the neck and torso. The teen stripped off his bloodied clothes, put on a clean pair of jeans and a T-shirt purloined from Weber's wardrobe, and hopped the G train back to Queens. When police arrested Katehis at a friend's house in Upstate New York, he was still wearing Weber's clothes.